From fc7cc951b606c9ea9044cd4b96cbdf9720761c64 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 18 Feb 2019 13:26:56 +0100 Subject: [PATCH] s390x/tcg: Fix TEST DATA CLASS instructions Let's detect normal and denormal ("subnormal") numbers reliably. Also test for quiet NaN's. As only one class is possible, test common cases first. While at it, use a better check to test for the mask bits in the data class mask. The data class mask has 12 bits, whereby bit 0 is the leftmost bit and bit 11 the rightmost bit. In the PoP an easy to read table with the numbers is provided for the VECTOR FP TEST DATA CLASS IMMEDIATE instruction, the table for TEST DATA CLASS is more confusing as it is based on 64 bit values. Factor the checks out into separate functions, as they will also be needed for floating point vector instructions. We can use a makro to generate the functions. Signed-off-by: David Hildenbrand Message-Id: <20190218122710.23639-2-david@redhat.com> Reviewed-by: Richard Henderson Signed-off-by: Cornelia Huck --- target/s390x/fpu_helper.c | 83 ++++++++++++++++----------------------- 1 file changed, 34 insertions(+), 49 deletions(-) diff --git a/target/s390x/fpu_helper.c b/target/s390x/fpu_helper.c index e921172bc4..0e9247bf7e 100644 --- a/target/s390x/fpu_helper.c +++ b/target/s390x/fpu_helper.c @@ -645,67 +645,52 @@ uint64_t HELPER(msdb)(CPUS390XState *env, uint64_t f1, return ret; } +/* The rightmost bit has the number 11. */ +static inline uint16_t dcmask(int bit, bool neg) +{ + return 1 << (11 - bit - neg); +} + +#define DEF_FLOAT_DCMASK(_TYPE) \ +static uint16_t _TYPE##_dcmask(CPUS390XState *env, _TYPE f1) \ +{ \ + const bool neg = _TYPE##_is_neg(f1); \ + \ + /* Sorted by most common cases - only one class is possible */ \ + if (_TYPE##_is_normal(f1)) { \ + return dcmask(2, neg); \ + } else if (_TYPE##_is_zero(f1)) { \ + return dcmask(0, neg); \ + } else if (_TYPE##_is_denormal(f1)) { \ + return dcmask(4, neg); \ + } else if (_TYPE##_is_infinity(f1)) { \ + return dcmask(6, neg); \ + } else if (_TYPE##_is_quiet_nan(f1, &env->fpu_status)) { \ + return dcmask(8, neg); \ + } \ + /* signaling nan, as last remaining case */ \ + return dcmask(10, neg); \ +} +DEF_FLOAT_DCMASK(float32) +DEF_FLOAT_DCMASK(float64) +DEF_FLOAT_DCMASK(float128) + /* test data class 32-bit */ uint32_t HELPER(tceb)(CPUS390XState *env, uint64_t f1, uint64_t m2) { - float32 v1 = f1; - int neg = float32_is_neg(v1); - uint32_t cc = 0; - - if ((float32_is_zero(v1) && (m2 & (1 << (11-neg)))) || - (float32_is_infinity(v1) && (m2 & (1 << (5-neg)))) || - (float32_is_any_nan(v1) && (m2 & (1 << (3-neg)))) || - (float32_is_signaling_nan(v1, &env->fpu_status) && - (m2 & (1 << (1-neg))))) { - cc = 1; - } else if (m2 & (1 << (9-neg))) { - /* assume normalized number */ - cc = 1; - } - /* FIXME: denormalized? */ - return cc; + return (m2 & float32_dcmask(env, f1)) != 0; } /* test data class 64-bit */ uint32_t HELPER(tcdb)(CPUS390XState *env, uint64_t v1, uint64_t m2) { - int neg = float64_is_neg(v1); - uint32_t cc = 0; - - if ((float64_is_zero(v1) && (m2 & (1 << (11-neg)))) || - (float64_is_infinity(v1) && (m2 & (1 << (5-neg)))) || - (float64_is_any_nan(v1) && (m2 & (1 << (3-neg)))) || - (float64_is_signaling_nan(v1, &env->fpu_status) && - (m2 & (1 << (1-neg))))) { - cc = 1; - } else if (m2 & (1 << (9-neg))) { - /* assume normalized number */ - cc = 1; - } - /* FIXME: denormalized? */ - return cc; + return (m2 & float64_dcmask(env, v1)) != 0; } /* test data class 128-bit */ -uint32_t HELPER(tcxb)(CPUS390XState *env, uint64_t ah, - uint64_t al, uint64_t m2) +uint32_t HELPER(tcxb)(CPUS390XState *env, uint64_t ah, uint64_t al, uint64_t m2) { - float128 v1 = make_float128(ah, al); - int neg = float128_is_neg(v1); - uint32_t cc = 0; - - if ((float128_is_zero(v1) && (m2 & (1 << (11-neg)))) || - (float128_is_infinity(v1) && (m2 & (1 << (5-neg)))) || - (float128_is_any_nan(v1) && (m2 & (1 << (3-neg)))) || - (float128_is_signaling_nan(v1, &env->fpu_status) && - (m2 & (1 << (1-neg))))) { - cc = 1; - } else if (m2 & (1 << (9-neg))) { - /* assume normalized number */ - cc = 1; - } - /* FIXME: denormalized? */ - return cc; + return (m2 & float128_dcmask(env, make_float128(ah, al))) != 0; } /* square root 32-bit */